Tool profile stationarity while simulating surface plastic deformation by rolling as a process of flat periodically reproducible deformation

Introduction. Surface plastic deformation is an effective way to improve the operating performance of machine parts. One of the promising approaches to the design of surface hardening technological processes is the technological inheritance mechanics. To calculate the hereditary parameters characterizing the accumulated deformation and damage to the metal, it is possible to simulate spinning as a process of plane fractional deformation, which significantly reduces the time required for modeling the process. However, upon rotation of the plane in which the stress-strain state is considered, the roller profile changes. The aim of the work is to assess the magnitude of the change in the roller profile in the deformation plane during deformation as an important factor ensuring the accuracy of the solution obtained. Research methods. The roll profile in the warp plane is defined by the intersection line of the roll surface and this plane. The paper presents the procedure for calculating the coordinates of the points of intersection lines, which are curves of the fourth order, depending on the geometric dimensions of the roller and the part, as well as the angle of inclination of the deformation plane. Results and discussion. To estimate the value of the roller profile change, the coordinates of the points of the intersection lines of the roller surface and the deformation plane are determined for the rolling modes corresponding to a sufficiently developed plastic deformation, the obtained lines are approximated in the coordinate system associated with the deformation plane, and the relative change in the coordinates of the intersection lines when the plane was rotated are estimated. As a result of the conducted analytical studies, it is found that even with developed plastic deformation, the relative change in the coordinates of the points of intersection lines does not exceed 0.1%. This indicates the possibility of using a stationary roller profile when simulating rolling using the plane fractional deformation model.